An expert found no evidence of a proper risk assessment being done before an employee was crushed to death at work, a court heard.

Marian Iancu died after two 200kg window panes he was trying to move toppled onto him at storage firm TLW (UK) Ltd in Rippleside Commercial Estate, Renwick Road, Barking on November 16, 2015.

His boss Han Rao, 34, from Deptford, pleads not guilty to manslaughter by gross negligence and breaching the Health and Safety at Work Act 1974. TLW denies failing to ensure the health, safety and welfare of employees.

Forensic consultant engineer Steven Tudor appeared at Mr Rao's Old Bailey trial on Thursday, January 23.

He told the court there was no evidence of a proper risk assessment, planning or supervision for the job.

"This operation constituted an obvious risk of serious injury or death," he said.

Jurors heard that only Mr Iancu, 39, and a workmate were attempting a task - putting broken skyscraper window panes in a skip - when six people were needed.

There was a risk the panes would fall because they were received upright rather than at an angle on a stillage frame, Mr Tudor said.

Prosecutor Andrew Thomas QC explained there is a "clear factual dispute" whether TLW told the men to do the job, or Chinese firm Yuanda which had a verbal agreement with Mr Rao to store materials. Yuanda staff were at TLW's premises on the day of the accident.

Safety procedures drawn up for Yuanda staff to do the job - which it was "contemplating" doing later the same week - were adequate, Mr Tudor confirmed.

But Mr Iancu was forced into a "danger zone" in front of the glass because it was the only way he could release the strapped together panes prior to their disposal, jurors heard.

Three companies' staff - Yuanda, TLW and DP Glass - were present the day Mr Iancu died.

The expert agreed with Graham Trembath QC, defending, that confusion might arise about who was responsible for a task in such circumstances and that instructions could be misunderstood.

Mr Rao argues he told his workers not to attempt the job.

However, when Mr Thomas asked where "the buck stopped" when it came to health and safety at work, Mr Tudor replied: "It's the employer."

The trial continues.